Local administration of a therapeutic agent involves the delivery of the agent to a specific organ or location in the body. In comparison, general systemic administration delivers a therapeutic agent to a much larger portion of the body. Thus one benefit associated with local administration over general systemic administration is a reduction in the amount of therapeutic agent lost during the treatment due to the unnecessary exposure of surrounding tissue to the agent. Minimizing the amount of therapeutic agent lost during treatment ultimately results in exposing the patient to a lower dosage of the agent.
Percutaneous delivery systems, such as medical catheter systems, are commonly used for the local administration of therapeutic agents to a desired treatment site within the body vessel through a minimally invasive, surgical procedure. Preferably, once the therapeutic agent is injected into the body vessel, the agent will flow downstream from the point of injection to the target site. This is particularly desirable when the therapeutic agent is a diagnostic agent used as a contrast medium or a mixture of embolization spheres or particles used to treat certain forms of cancer. Since a multiple balloon catheter normally delivers the therapeutic agent along the entire length of the balloon, it is likely that the combination of injection dynamics and fluid rheology will result in the therapeutic agent traveling upstream or away from the desired target, as well as downstream towards the target. Accordingly, there exists a need to provide a percutaneous delivery system that minimizes the loss of a therapeutic agent by enhancing the ability of the therapeutic agent to selectively flow downstream for delivery to the targeted site.